diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/e_ilogb.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/e_ilogb.c | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/sysdeps/ieee754/dbl-64/e_ilogb.c b/sysdeps/ieee754/dbl-64/e_ilogb.c index 0452a71fb8..1e338a59c1 100644 --- a/sysdeps/ieee754/dbl-64/e_ilogb.c +++ b/sysdeps/ieee754/dbl-64/e_ilogb.c @@ -25,30 +25,39 @@ static char rcsid[] = "$NetBSD: s_ilogb.c,v 1.9 1995/05/10 20:47:28 jtc Exp $"; #include <math.h> #include <math_private.h> -int __ieee754_ilogb(double x) +int +__ieee754_ilogb (double x) { - int32_t hx,lx,ix; + int32_t hx, lx, ix; - GET_HIGH_WORD(hx,x); - hx &= 0x7fffffff; - if(hx<0x00100000) { - GET_LOW_WORD(lx,x); - if((hx|lx)==0) - return FP_ILOGB0; /* ilogb(0) = FP_ILOGB0 */ - else /* subnormal x */ - if(hx==0) { - for (ix = -1043; lx>0; lx<<=1) ix -=1; - } else { - for (ix = -1022,hx<<=11; hx>0; hx<<=1) ix -=1; - } - return ix; + GET_HIGH_WORD (hx, x); + hx &= 0x7fffffff; + if (hx < 0x00100000) + { + GET_LOW_WORD (lx, x); + if ((hx | lx) == 0) + return FP_ILOGB0; /* ilogb(0) = FP_ILOGB0 */ + else /* subnormal x */ + if (hx == 0) + { + for (ix = -1043; lx > 0; lx <<= 1) + ix -= 1; } - else if (hx<0x7ff00000) return (hx>>20)-1023; - else if (FP_ILOGBNAN != INT_MAX) { - /* ISO C99 requires ilogb(+-Inf) == INT_MAX. */ - GET_LOW_WORD(lx,x); - if(((hx^0x7ff00000)|lx) == 0) - return INT_MAX; + else + { + for (ix = -1022, hx <<= 11; hx > 0; hx <<= 1) + ix -= 1; } - return FP_ILOGBNAN; + return ix; + } + else if (hx < 0x7ff00000) + return (hx >> 20) - 1023; + else if (FP_ILOGBNAN != INT_MAX) + { + /* ISO C99 requires ilogb(+-Inf) == INT_MAX. */ + GET_LOW_WORD (lx, x); + if (((hx ^ 0x7ff00000) | lx) == 0) + return INT_MAX; + } + return FP_ILOGBNAN; } |